抑癌基因PTEN突变在软组织肉瘤中的研究

目的本研究探讨软组织肉瘤中PTEN突变及与软组织肉瘤发生发展的相关性。方法应用聚合酶链反应．单链构象多态性分析（PCR．SSCP）方法以及DNA测序技术,扩增86例软组织肉瘤PTEN基因的第5～8外显子,根据构象改变检测其基因突变情况。结果86例软组织肉瘤中检测到2例突变：第8外显子第351位密码子由T→C的错义突变,突变使蛋白结构由苯丙氨酸突变为赖氨酸;第8外显子第334位密码子由A→T的错义突变,突变使蛋白结构由天门冬酰胺突变为赖氨酸。结论软组织肉瘤中存在PTEN抑癌基因的突变,但突变率很低,可能在STSs的发生发展中不起主要作用。     

脂肪肉瘤c-myc和p53基因蛋白的表达及意义

背景与目的：原癌基因c-myc和抑癌基因p53与脂肪肉瘤的关系的研究较少,脂肪肉瘤中是否存在p53基因突变文献报道不一,本文拟探讨脂肪肉瘤中c-myc、p53基因蛋白表达的水平及意义,以期为本组肿瘤发生发展及病理诊断、鉴别诊断提供一定的分子生物学资料。方法：采用链菌素抗生物素－生物素（labelled streptavidin-biotin,LSAB)免疫组化法、聚合酶链反应－单链构象多态性分析（Single strand conformation polymorphism analysis of polymerase chain reaction products,PCR-SSCP)及DNA序列分析方法。结果：c-myc和p53蛋白在脂肪肉瘤表达阳性率分别为38．09％（16／42）和48．08％（25／52）。不同类型脂肪肉瘤,分化良好者阳性率均明显低于分化较差者。脂肪肉瘤中c-myc和p53蛋白表达呈正相关。c-myc和p53蛋白表达在原发者和复发者之间的差异均无统计学意义。p53第6、7、8外显子PCR－SSCP分析,2例多形性脂肪肉瘤出现异常泳动带。DNA序列分析证实1例第8外显子第268位编码区出现错义突变（AAC→ATC）,另1例第6例显子第221位编码区出现可疑杂合性同义突变（GAG→GAA)。结论：c-myc和p53蛋白与脂肪肉瘤的形成及分化和恶性程度有关。它们可作为判断脂肪肉瘤分化程度及恶性程度参考指标之一,但与肿瘤复发无关。在脂肪肉瘤发生发展中两者可能起协同作用。脂肪肉瘤中p53基因第6、8外显子分别存在点突变。     

乙肝病毒/黄曲霉毒素B1双暴露相关性肝细胞癌的p53基因249位点突变与p53蛋白表达的关系

目的研究乙肝病毒/黄曲霉毒素B1双暴露相关性肝细胞癌的p53基因249位点突变与p53蛋白表达关系。方法通过IHG特殊免疫组织化学法检测55例手术切除经病理证实为原发性肝癌的HCC组织及10例正常肝组织中AFB1-DNA加合物的暴露情况,并根据是否同时存在HBV暴露加以分组,通过免疫组化S-P法检测并比较各组间p53蛋白的表达情况。同时,通过PCR结合直接测序的方法检测其p53基因第7外显子249密码子的突变情况。结果 p53基因第7外显子249位点的突变在实验组A与对照组C中均具有较高阳性突变率,其突变率分别为68.75%(22/32)、63.64%(7/11),在对照组B中的突变率较低,为16.67%(2/12),在正常对照组中无1例出现有突变。其中实验组A与对照组B及正常对照组D的比较差异具有统计学意义(P<0.05),而与对照组C比较差异无统计学意义(P>0.05);p53蛋白在其基因249位点突变阳性组与阴性组中的表达阳性率分别为92.86%(26/28)、60.87%(16/27),差异具有统计学意义(P<0.05)。结论 HCC的发生过程中,AFB1暴露与p53第7外显子249位点的突变密切关系相关,当同时存在乙肝病毒暴露的协同作用的情况下突变率更高;p53基因的突变可能是造成HCC中p53蛋白高表达的重要因素之一。     

乳腺增生病p53基因第8外显子突变及p53蛋白表达

目的：探讨p53基因在乳腺癌发生早期的作用。方法：用免疫组化检测36例乳腺单纯增生，31例不典型增生，30例乳腺癌组织中p53蛋白表达，用PCR－RFLP检测p53基因第8外显子第278密码子突变。结果：乳腺单纯性增生，不典型增生和乳腺癌中p53蛋白表达率分别为0，22．6％，46．7％。p53基因第8外显子的突变率分别为0，3．2％，10．0％，均为杂合子突变。结论：乳腺癌不典型增生中存在p53蛋白表达和该基因第8外显子突变，该突变可能在乳腺增生病向乳腺癌进展过程中起一定作用。     

乙肝病毒/黄曲霉毒素B1双暴露相关性肝细胞癌的p53基因249位点突变与p53蛋白表达的关系

目的研究乙肝病毒/黄曲霉毒素B1双暴露相关性肝细胞癌的p53基因249位点突变与p53蛋白表达关系。方法通过IHG特殊免疫组织化学法检测55例手术切除经病理证实为原发性肝癌的HCC组织及10例正常肝组织中AFB1-DNA加合物的暴露情况,并根据是否同时存在HBV暴露加以分组,通过免疫组化S-P法检测并比较各组间p53蛋白的表达情况。同时,通过PCR结合直接测序的方法检测其p53基因第7外显子249密码子的突变情况。结果 p53基因第7外显子249位点的突变在实验组A与对照组C中均具有较高阳性突变率,其突变率分别为68.75%（22/32）、63.64%（7/11）,在对照组B中的突变率较低,为16.67%（2/12）,在正常对照组中无1例出现有突变。其中实验组A与对照组B及正常对照组D的比较差异具有统计学意义（P〈0.05）,而与对照组C比较差异无统计学意义（P〉0.05）;p53蛋白在其基因249位点突变阳性组与阴性组中的表达阳性率分别为92.86%（26/28）、60.87%（16/27）,差异具有统计学意义（P〈0.05）。结论 HCC的发生过程中,AFB1暴露与p53第7外显子249位点的突变密切关系相关,当同时存在乙肝病毒暴露的协同作用的情况下突变率更高;p53基因的突变可能是造成HCC中p53蛋白高表达的重要因素之一。     

食管鳞状细胞癌p53基因杂合性缺失和基因突变的相关研究

 目的 检测食管鳞状细胞癌（ESCC）中p53基因杂合性缺失（LOH），p53基因突变及蛋白表达的情况，分析其与临床病理和预后的相关性。方法 采用聚合酶链反应-单链构象多态性分析（PCR-SSCP）和免疫组织化学方法（SP）检测56例ESCC中p53基因LOH和p53基因蛋白的表达情况。结果 56例ESCC组织中p53蛋白阳性表达率为60.7 %（34／56），它与患者的年龄、性别和家族史无关（P＞0.05），有或无淋巴结转移的阳性率分别为81.0 %（17／21），48.6 %（17／35）；生存率低于3年组和高于3年组的p53阳性表达率为73.9 %（17／23），46.4 %（13／28），差异有统计学意义。p53基因LOH率为80.5 %（33／41），与患者的年龄、性别、家族史和有无淋巴结转移无关，与3年生存率有相关性（P＜0.05）。p53基因总突变率为76.8 %（43／56），突变位于17号染色体第4外显子者5例，第5外显子者23例，第6外显子者1例，第7外显子者4例，第8外显子者7例，有3例在内含子。p53基因突变／过度表达率为46.4 %（26／56），两种方法检测的符合率为55.4 %（31／56）。结论 p53基因在ESCC的发生、发展中可能发挥重要作用，伴有p53基因LOH／p53蛋白过度表达的3年生存率明显降低。p53蛋白阳性表达的ESCC更易发生淋巴结转移，可作为判断食管癌预后的参考指标之一。     

p53基因在甲状腺癌中的突变研究

目的:为探讨p53基因突变与甲状腺癌的发生、发展及预后的关系.方法:应用PCR单链构象多态性(SSCP)分析技术,对p53基因第7,8外显子突变进行了检测和分析.结果:在37例甲状腺癌中有11例在第7.8外显子发生突变,突变率为29.9%.p53基因突变在复发的患者中显著高于未复发的患者;p53基因突变与转移、组织学类型和分化状况无显著差异.结论:p53基因的突变可能与甲状腺癌患者预后有关.     

p53基因在甲状腺癌中的突变研究

目的：为探讨p53基因突变与甲状腺癌的发生、发展及预后的关系。方法：应用PCR单链构象多态性（SSCP）分析技术,对p53基因第7,8外显子突变进行了检测和分析。结果：在37例甲状腺癌中有11例在第7.8外显子发生突变,突变率为29.9％。p53基因突变在复发的患者中显著高于未复发的患者;p53基因突变与转移、组织学类型和分化状况无显著差异。结论：p53基因的突变可能与甲状腺癌患者预后有关。     

子宫内膜样腺癌组织中P53、P63和C-erbB2的表达及其意义

背景与目的:p53与C-erbB2是已被证实与子宫内膜样腺癌(endometrioidadenocarcinoma,EC)密切相关的抑癌基因和癌基因,而它们之间的相关性报道较少。p63在结构上与p53高度同源,被认为是p53突变时的一种抑癌基因,它的抑癌特性尚未确定,它在EC中的表达少见文献报道。本研究旨在探讨p53、p63和C-erbB-2基因在EC发生发展中的作用及其与EC临床病理特征的关系。方法:采用免疫组化SP法检测38例EC和23例子宫内膜增生过长(endometrialhyperplasia,EH)及10例正常增生期子宫内膜(benignproliferativeendometrium,BPE)中P53、P63和C-erbB2蛋白的表达情况。结果:(1)P53蛋白在EC组中的阳性率为31.6%,明显高于EH组和BPE组(P<0.05)。P53的表达与EC的手术病理分期和肌层浸润深度有关(P<0.005),而与组织学分级无关(P>0.05)。(2)P63蛋白在EC组中的阳性率为81.6%,与EH组、BPE组比较,差异均有统计学意义(P<0.005)。P63的表达与EC的组织学分级、手术病理分期和肌层浸润深度均无关(P>0.05)。(3)C-erbB2蛋白在EC组中的阳性率为23.2%,与EH组、BPE组比较,差异均无统计学意义(P>0.05)。C-erbB2的表达与EC的手术病理分期和肌层浸润深度有关(P<0.001,P<0.005),而与组织学分级无关(P>0.05)。(4)P53和P63在EC中的表达呈正相关(r=0.443,P<0     

p53和p21WAF1蛋白在肝细胞肝癌中表达的意义

 【摘要】　目的　探讨p53和p21WAF1蛋白在肝细胞肝癌（HCC）中的表达及其意义。方法　应用免疫组织化学SP法检测41例HCC及相应30例癌旁肝组织中p53和p21WAF1蛋白的表达。结果　p53和p21WAF1蛋白在HCC中阳性表达率分别为43.9 ％和75.6 ％，明显高于癌旁组织，差异有统计学意义（P＜0.01）。HCC中p53蛋白表达与p21WAF1蛋白表达无明显相关性（P＞0.05）。p53蛋白表达在不同组织学分级、有无肝内或门静脉转移之间差异有统计学意义，而p21WAF1蛋白表达在不同临床病理特征间差异无统计学意义。结论　p53和p21WAF1蛋白高表达均在HCC发生、发展中起作用，但两者间并无相关性。p21WAF1的诱导存在着不依赖p53的途径。     

突变型p53基因与肝细胞癌组织学分级、转移、肿块大小和包膜形成的相关性研究

目的：探讨突变型p53基因与肝细胞癌组织学分级、转移、肿块大小和包膜形成的相关性。方法：随机选择41例肝细胞肝癌患者的癌和癌旁肝组织标本，SP法检测其p53蛋白表达，分析突变型p53基因与肝细胞癌组织学分级、转移、肿块大小和包膜形成的相关性。结果．p53在癌和癌旁肝组织中阳性表达率分别为43．9％和6．67％，两者比较，差异显著（P〈0．01）；p53蛋白阳性表达率，Ⅲ-Ⅳ级肝癌明显高于Ⅰ～Ⅱ级肝癌，发生转移（血道或淋巴道转移）肝癌明显高于未发生转移（血道或淋巴道转移）肝癌，两者之间比较，差异有显著性意义（P〈0．05）；但p53蛋白阳性表达率与肝癌组织大小和其是否有包膜无关（P〉0．05）。结论：突变型p53基因与肝细胞癌组织学分级、转移密切相关，但与肝癌组织大小和包膜形成无关。     

Analysis of the c-myc, K-ras and p53 Genes in Methylcholanthrene induced Mouse Sarcomas

We have examined 63 methylcholanthrene (MCA)-induced mouse sarcomas for possible correlations of mutations involving the c-myc, ras and p53 genes. The c-myc gene was found to be amplified in 18 of these sarcomas (29%). Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and subsequent direct sequencing identified 18 cases carrying K-ras mutation at codons 12, 13 and 61 (29%). No mutation was detected in the H-ras and N-ras genes. Mutations of the p53 gene in exons 5 to 8 were found in 45 cases (71%). Comparison of these mutations revealed that out of 18 cases with c-myc gene amplifications, 10 carried K- ras mutations (56%) and 14 carried p53 mutations (78%). In contrast, among 45 cases of sarcomas without c-myc gene amplification, 8 were found to have K- ras mutations (18%). The same 45 cases were found to have 31 p53 mutations (69%). The present study suggests a strong correlation between c-myc gene amplification and K- ras gene mutation ( P < 0.01). p53 gene mutation was frequently found among MCA-induced mouse sarcomas, indicating the importance of this mutation in the etiology of these tumors. However, p53 mutations were present in sarcomas regardless of the state of c-myc amplification and K- ras mutation. Therefore, a defect in the p53 gene is independent of amplification of the c-myc gene or point mutation of the K- ras gene.     

Analysis of the c-myc, K-ras and p53 genes in methylcholanthrene-induced mouse sarcomas.

We have examined 63 methylcholanthrene (MCA)-induced mouse sarcomas for possible correlations of mutations involving the c-myc, ras and p53 genes. The c-myc gene was found to be amplified in 18 of these sarcomas (29%). Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and subsequent direct sequencing identified 18 cases carrying K-ras mutation at codons 12, 13 and 61 (29%). No mutation was detected in the H-ras and N-ras genes. Mutations of the p53 gene in exons 5 to 8 were found in 45 cases (71%). Comparison of these mutations revealed that out of 18 cases with c-myc gene amplifications, 10 carried K-ras mutations (56%) and 14 carried p53 mutations (78%). In contrast, among 45 cases of sarcomas without c-myc gene amplification, 8 were found to have K-ras mutations (18%). The same 45 cases were found to have 31 p53 mutations (69%). The present study suggests a strong correlation between c-myc gene amplification and K-ras gene mutation (P < 0.01). p53 gene mutation was frequently found among MCA-induced mouse sarcomas, indicating the importance of this mutation in the etiology of these tumors. However, p53 mutations were present in sarcomas regardless of the state of c-myc amplification and K-ras mutation. Therefore, a defect in the p53 gene is independent of amplification of the c-myc gene or point mutation of the K-ras gene.     

乳腺导管内增生病变中p53表达与外显子突变的研究

目的：肿瘤抑制基因p53异常是浸润性乳腺癌发生发展中常见事件,而其与包括普通型增生（usualductal hyperplasia,UDH）、不典型增生（atypical ductal hyperplasia,ADH）及导管内原位癌（ductal carcinoma insitu,DCIS）的乳腺导管内增生性病变关系不明。本研究旨在探讨乳腺导管内增生性病变中p53外显子突变及突变型p53蛋白表达情况,以期了解p53突变及蛋白表达在乳腺癌发生发展中的作用。方法：用高分辨率熔解曲线（high-resolution melting,HRM）结合测序研究140例乳腺导管内增生性病变中p53外显子5-8的突变情况。用免疫组化研究240例乳腺导管内增生性病变中突变型p53蛋白表达情况。结果：经过HRM分析,共17例患者DNA熔解曲线与野生型标准品熔解曲线大于阈值结合测序分析结果发现,其中16例出现p53外显子突变。p53在UDH、ADH及DCIS中的突变率为0.0%（0/40）,12.7%（8/63）和21.6%（8/37）,三者间差异显著（P〈0.05）。40例UDH中未出现突变型p53蛋白阳性表达,在14.6%（19/130）的ADH出现阳性表达,在31.4%（22/70）的DCIS中出现阳性表达,三者间差异显著（P〈0.05）。Spearman相关性分析示突变型p53蛋白表达与p53外显子突变呈正相关（r=0.792,P〈0.01）。结论：p53外显子突变及突变型p53蛋白表达发生于乳腺导管内增生性病变中的ADH与DCIS,其可能为乳腺癌发生发展中的早期事件。     

p53 expression and its relationship to DNA alterations in bone and soft tissue sarcomas.

The p53 gene is one of the best studied tumour suppressor genes. Recently we performed mutation analysis on the p53 gene in a large number of bone and soft tissue sarcomas, and found that approximately one-third of the sarcomas have some type of DNA alteration at the p53 locus (Toguchida et al., 1992). However, the expression of the p53 protein resulting from these alterations still remains to be clarified. In this study, p53 expression in the sarcoma tissues was analysed immunohistochemically using antibody PAb421 (Oncogene Science) and its relationship to DNA alterations was examined. Of 113 tumours, 29 (25.7%) showed positive staining for the p53 protein. These included 19 of 67 osteosarcomas, five of 20 chondrosarcomas, four of 11 malignant fibrous histiocytomas (MFHs) and one Ewing''s sarcoma. In chondrosarcomas, most of the p53-positive tumours belonged to highly malignant and atypical tumour types (dedifferentiated or mesenchymal type), suggesting a role for p53 mutation in the progression of cartilaginous tumours. All the cases with a missense mutation showed strongly positive staining, while no immunoreactivity was observed in the remaining three-quarters with DNA alterations including gross rearrangement, frame-shift mutation, nonsense mutation or mutation at splicing site except in one case. These results demonstrated the dominance of the p53 mutations with null protein expression in bone and soft tissue sarcomas, showing a unique characteristic of these types of tumours compared with other malignancies such as colon carcinomas.     

Demonstration of ras and p53 Gene Mutations in Carcinomas in the Forestomach and Intestine and Soft Tissue Sarcomas Induced by N-Methyl-N-nitrosourea in the Rat

The presence of ras family and p53 gene mutations in rat forestomach, intestine and liver tumors and soft tissue sarcomas induced by N methyl- N -nitrosourea (MNU) was examined using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) followed by direct sequencing analysis. In the forestomach squamous cell carcinomas (SCC), Ha- ros and p53 mutations were detected in 2 (40%) and 4 (80%) of 5 cases, respectively. The figures for Ki- ras and p53 gene mutations in adenocarcinomas of the large and small intestines were 3 (18.8%) and 5 (31.3%) of 16 cases. Soft tissue sarcomas in different sites were found to have mutations of Ki- ras in 7 (23.3%)and of p53 in 9 (30%) of 30 cases. One forestomach SCC and 2 soft tissue sarcomas had double p53 mutations in different exons. Single cases of forestomach SCC and intestinal adenocarcinoma had mutations in both Ki- ras and p53 genes. No mutations were found in counterpart benign tumors or hepatocellular adenomas. The p53 mutation spectrum revealed preferential clustering within exon 8 for the forestomach SCCs, and exons 5 and 8 for the intestinal adenocarcinomas, whereas the distribution was evenly spread through exons 5 to 8 in soft tissue sarcomas. All the detected ras or p53 mutations were G:C to A:T transitions. These results indicate firstly that specific Ki- ras , Ha- ras and p53 gene mutations in MNU-induced lesions are related to particular alkylation sites (G:C to A:T transitions) and secondly, although not essential, Ki- ras , Ha- ras or p53 gene mutations may be involved in the progression stage of forestomach, intestine and soft tissue neoplasms induced by MNU.     

Analysis of p53 mutational events and MDM2 amplification in canine soft-tissue sarcomas.

Canine cancer is of major significance in terms of animal health and welfare and soft tissue sarcomas are an important group of tumours accounting for approximately 15% of all canine tumours presented. Abnormal p53 protein expression and gene mutations have been identified in a number of different canine tumour types. However, mdm2 gene amplification has only been investigated in a limited number of canine osteosarcomas. In this present study a series of canine soft-tissue sarcomas (STS) were examined for p53 mutations and/or mdm2 amplification. For p53 mutational studies polymerase chain reaction and direct DNA sequencing was used. Gene mutations were identified in 6 of 30 (20%) primary tumour cases including MPNST (n=3) leiomysarcoma (n=1), heamangiosarcoma (n=1) and sarcoma (n=1). mdm2 gene amplification was assessed by Southern Blot. Although there was no evidence for major gene rearrangements, gene amplification was detected in 4 of 35 (11.4 %) primary tumours including MPNST (n=2), rhabdomyosarcoma (n=2). A total of 33 cases were examined for both p53 mutations and mdm2 amplification. Seven of the tumours were positive for p53 mutations, while five were positive for mdm2 amplification. With the exception of one case, a reciprocal relationship between the presence of a p53 mutation and mdm2 gene amplification was demonstrated.     

Overexpression and mutation of p53 in epithelial ovarian cancer

We examined p53 expression in 107 epithelial ovarian cancers with immunohistochemical techniques using monoclonal antibody PAb1801. High level expression of nuclear p53 protein was detected in the malignant epithelium in 54 (50%) of these cancers. Expression of p53 protein was undetectable in 13 benign gynecological tissues. p53 mRNA from three cancers that overexpressed the protein were sequenced and point mutations which altered the coding sequence of the highly conserved region of the gene were found in each case. Three cancers with undetectable protein levels also were sequenced and were found to be wild-type through the same region of the gene. As in other cancers, overexpression of the p53 protein in ovarian cancer appears to correlate closely with the presence of mutation in the p53 gene. p53 overexpression did not correlate with stage, histological grade, or the ability to perform optimal cytoreductive surgery. A significant correlation (P = 0.04) was observed between p53 overexpression and aneuploidy in advanced stage (III/IV) disease. There was no significant relationship between overall survival and p53 expression. Since mutation and overexpression of p53 are common in epithelial ovarian cancers, further studies are warranted to clarify the role of p53 in ovarian tumorigenesis.     

nm23蛋白在软组织肉瘤中的表达及意义

目的探讨nm23蛋白在软组织肉瘤中的表达及与软组织肉瘤分级的关系。方法应用FNCLCC（法国癌症中心联盟）分级系统对108例软组织肉瘤进行组织病理学分级并应用免疫组织化学技术Evision二步法检测nm23蛋白在这些肿瘤中的表达情况。结果108例软组织肉瘤中1级、2级、3级分别为23例、28例和57例；免疫组织化学染色结果显示，在1级、2级、3级中nm23蛋白的阳性表达率分别为26．1％、32．1％、61．4％，经卡方检验P〈0．05，差异有显著性。结论nm23蛋白表达与软组织肉瘤组织学分级相关并且分级越高阳性表达率越高，因此nm23在软组织肉瘤中可能扮演着促进肿瘤浸润与转移的作用。     

人肝细胞癌及癌旁组织中p53蛋白和PCNA的表达

应用免疫组化方法检测了７３例肝细胞癌及癌旁组织中ｐ５３蛋白的表达，７０例肝细胞癌及癌旁组织中ＰＣＮＡ的表达。结果ｐ５３蛋白、ＰＣＮＡ在肝细胞癌中阳性表达率显著高于癌旁组织，且与肝细胞癌分化程度密切相关。癌旁组织中，ｐ５３蛋白表达仅见于增生结节中，肝硬化组织均为阴性；增生结节中ＰＣＮＡ阳性表达显著高于肝硬化组织。提示ｐ５３基因突变是肝细胞癌的频发事件，在肝细胞癌的发生发展中起重要作用；增生结节细胞的增殖活性增强，是肝细胞癌的癌前病变。作者还讨论了ｐ５３蛋白和ＰＣＮＡ表达间的关系